Together with suit, mask and fins, a jacket is also used for deep diving activities. The jacket has pockets where various tools to be used by a diver can be arranged.
Such tools include weights, generally made of lead and generally arranged into casings, which weights are intended to cancel out or reverse a difference between hydrostatic thrust of the body and the diving suit on one side, and the corresponding weight on the other side.
The pockets of the jacket are generally provided with a sealing or locking arrangement. If such jackets are intended to contain weights, such arrangement is provided in part on the pocket of the jacket and in part on the casing of the weights, to facilitate insertion and extraction of the casing.
A widely used sealing arrangement includes a buckle with elastic snap engagement and release properties, such as the buckles known as FAST® buckles. Such buckles generally include a male part, provided with elastically deformable arms, able to be inserted inside a female part or sheath. The elastically deformable arms comprise transversal stop abutments, suitable for engagement with corresponding transversal stop abutments projecting inside the sheath. In order to open the buckle it is necessary to intentionally press such elastically deformable arms, perpendicularly to their longitudinal direction, to release the stop abutments of the male part from the stop abutments of the sheath. In order to allow such operation, the sheath includes openings that allow the ends of the arms to be pressed, thus releasing the abutments that keep them anchored to the sheath.
In general, the arms and the opposite surfaces of the sheath are so shaped to push the male part of the buckle out from the sheath when the stop abutments of the male part are released from the stop abutments of the female part, thus allowing the arms to go back into their undeformed position. Such type of buckles are known, for example, from FIG. 2 of U.S. Pat. No. 4,831,694, which patent is incorporated herein by reference in its entirety.
However, the diver is often equipped with gloves of substantial thickness. As a consequence, transversal squashing of the deformable arms through suitable slits arranged in the sheath may become difficult. In this respect, in the above mentioned U.S. Pat. No. 4,831,694, the transversal squashing action of the deformable arms is carried out by sliding of a sleeve surrounding the buckle.
Also sliding of the sleeve itself on the buckle can be difficult for the diver, though. In this respect, U.S. Pat. No. 6,487,761, also incorporated herein by reference in its entirety, facilitates the opening of the buckle and allows release of the stop abutments of the deformable arms of the male part from the stop abutments of the female part or sheath, by providing a handgrip connected to the male part of the buckle through a flexible connection arrangement. In particular, by pulling the handgrip, the diver releases the flexible arms of the male part from the stop abutments of the sheath and, continuing such pulling action, also extracts the casing of the weights together with the male part of the buckle.
However, in the above mentioned FAST® buckles, as soon as the ends of the flexible arms are released from the abutments of the sheath, the male part of the buckle is forced to automatically come out of the sheath, thus causing opening of the buckle. Therefore, an accidental knocking of the handgrip against a rock or a rigid body can cause the buckle to open and the casing of the weights to be lost as a consequence.
A further drawback in addition to the one mentioned above occurs when the diver wants to place the casing of the weights back in the pocket immediately after extraction of such casing. Such operation is rather complex when the diver is underwater, as the weights, instead of being a single rigid element (e.g., a parallepiped-shaped element), usually include several loose elements causing deformation of the casing and requiring a hand-guided movement in order to be correctly inserted into the pocket, upon which insertion the male part of the buckle has to be guided into the female part thereof to prevent the casing from accidentally coming out.
In order to overcome the first drawback, Italian patent No. 1,361,976, in the name of the same applicant of the present application and incorporated herein by reference in its entirety, provides for two consecutive voluntary operations in order to open the buckle. In a first step, a locking element is extracted by pulling the handgrip. In a subsequent step, by continuing the pulling action on the handgrip, the male element of the buckle is extracted from the sheath. Therefore, accidental knocking of the handgrip against a rigid body cannot cause an involuntary opening of the buckle with consequent loss of the casing of the weights.
In order to overcome the second drawback, as also provided in the above mentioned Italian patent, the part of the buckle applied to the casing of the weights is arranged on a rigid plate. Such rigid plate facilitates the diver's introduction of the casing in the pocket of the jacket when underwater.
In European patent EP 1,864,586, also in the name of the same applicant of the present application and incorporated herein by reference in its entirety, a buckle with a more compact shape is provided, where involuntary opening is further prevented. According to this patent application, a pulling action exerted on the handgrip initially causes an auxiliary element to slide inside the male element of the buckle, where the male element is provided with inclined surfaces sliding on corresponding inclined surfaces of the deformable arms of the male element, deforming such arms to release their stop surfaces from the stop surfaces of the female part.
Therefore, by pulling the handgrip connected to the male part of the buckle, a progressive sliding of such inclined surfaces occurs, with a consequent bending of the deformable arms, until release of the transversal abutment surfaces on the deformable arms from the corresponding transversal abutment surfaces of the sheath, so that the casing of the weights can be extracted from the pocket of the jacket.
It should be noted that interruption of the pulling action on the handgrip during the mutual sliding step of the inclined surfaces causes the elasticity of the deformable arms to invert the sliding movement, thus bringing the buckle back into the starting closed position. In such way, accidental knocking is prevented from opening the buckle.
It should also be noted that, when the diver is underwater, inserting a previously extracted casing of the weights into the pocket of the jacket is complicated by the fact that the pocket generally has a larger cross section than that of the casing, so that several attempts may be needed before a correct insertion of the male part in the sheath occurs, both the male part and the sheath being smaller than the pocket in cross section.